Potential oil formations in New Zealand, and their stratigraphic position as related to basin evolution

Abstract

Seven oil-prospective basins are recognised in New Zealand, and their stratigraphy is reviewed. Potential oil formations, which range in age from Upper Cretaceous to Pliocene, are discussed for each basin. Their particular position in the stratigraphic column is largely controlled by the local tectonic history.In anyone basin, possible source and reservoir rocks are in about the same stratigraphic position and generally closely related to each other. In five of the seven basins, which are characterised as epicontinental, unstable shelf areas, they generally occur near the base of the whole sedimentary sequence; this is shown to be inherent to the paleogeographic setting and particular tectonic evolution, and is consistent with the pattern found under similar conditions in other parts of the world. The characteristic lithologic assemblage of possible source sequences found here is of the shale-sandstone-coal type, and its environment is a transitional one of the near-shore marine and deltaic or estuarine-brackish to freshwater zone.Additional potential reservoir formations occur in some of the basins higher up in the section. They are formed by sandstone as well as carbonate rocks, and their presence is discussed in relation to the local tectonic history.

Integrating earth and life sciences in New Zealand natural history: The parallel arcs model

“…Croizat (1958) proposed correlation between biogeographic tracks and the localities of oil deposits. Katz (1968) reviewed the potential oil formations in New Zealand, which are all found on epicontinental, unstable shelf areas. The characteristic lithologic assemblage of possible source sequences is of the shale-sandstonecoal type, and "its environment is a transitional one of the near-shore marine and deltaic or estuarinebrackish to freshwater zone".…”

Cenozoic stratigraphy and structure of Karamea-Little Wanganui district, Buller, South Island, New Zealand

“…However, the Blue Duck Anticline, which has thick Late Miocene strata along its crest, did not grow till later. Blue Duck and Arapito Anticlines are the best gas/oil targets in the mapped area, but source rocks younger than Oligocene are supposedly absent from the West Coast (Katz 1968). The distribution of Tongaporutuan, sandy, calcite-cemeted shellbeds indicates derivation of these beds from shorelines to the southeast, as do the slumped strata in Ray Creek.…”

Miocene foraminiferal environments: Tarakohe Mudstone, Western Nelson

“…Elucidation of the history of the Taranaki-Wanganui basin (Katz, 1968) now being prospected for oil can be advanced by paleoenvironmental interpretation of formations on its flanks. VOL.…”